The Twelfth International Congress for Electron Microscopy will convene in Seattle in August of 1990 as the first world EM Congress to be held in the United States since 1962. This milestone event will establish the directions and objectives for the theory and practice of microscopy and determine research priorities for the remainder of the century. It is being organized by the Electron Microscopy Society of America in cooperation with the Microbeam Analysis Society under the authorization of the International Federation of Societies for Electron Microscopy. Although the emphasis will be on electron microscopy, other advanced forms of imaging, such as confocal microscopy and scanning tunneling microscopy, will also receive full coverage. The scientific program is arranged around some 55 symposia with about 250 lectures by recognized international experts on imaging of biological, crystalline and amorphous materials, the fundamentals of microanalysis and applications of advanced imaging and analytical techniques to the biosciences and medicine.